Connection for measuring instruments.



Patented Nov. ll, I902.

No. 7l3,583.

- J. E. WOGDBFHDGE.

CONNECTION FOR MEASURING INSTRUMENTS.

4.5.p171ication filed Mair. 26, 1902.

(No Model.)

i 4 a as Fig.5.

r||M ||I 4 7 1,25%

Inventor: Jonathan E. (Doodbr'udge.

@Ltnesses.

THE NORRIS PETERS co., WASHINGTON, 0. c4

6 UN A 'HAY E.

ERAL ELECTRIC COMPANY, A CORPGRATION OF NEYV YORK.

CUNNECTlQW 5 08 e'UQlNG lNSTRUlVl ENTS.

SEECIFICAEIQN forming part 0: Letters Eatent No, 713,588, dated blovember, 11, 1992., Application filed March 26, 1902. Serial No. 100,896, (lilo model.)

when it NZ-(l Z/ conceive:

that I, JONATHAN Ween- BPLIDGE, citizen of the United States, resid Albany, county of Albany, State of jerk, have invented certain new and izsefnl Improvements Systems of Conneci cr Measuring; instruments, {Case No.

132, of which the following is e specificer inctrnrnente would otherwise for tofor Inasmuch as the three ground connections leads of each pair 0L emmeter-leecls, one or? the three return-wires for the emmeters may v be used as a common return. Inasmuch, however, as the common return, in a; second; 31' three-pheee system carries; no current when the primary system has no common return, this wire also may be omitted, thereby permitting the number of leerls for the three emrneters to be reduced from six to three.

Fig. 1 represents the olti errengementa-bove referred to, the three meine of the tlii eephese system being indicated at 1, 2, and 3, the three cutreet-trensformers therefor at 9 6 end the connected to iee o7tlzese transformers at 8, ierninal of' eeclz eecon leiyis indicated at 10, ll, 12, rei heee ground connections operate e 5 connection between the three He from which the ground conneclesteeziyllereferepf connectof eaometer-lensie sepaennd, 1, it will be seen cennectioe to ground, centeci at 13 in Fig. This conneca reduction of the leads for ul cnerents in the other twomains of he system, i have found that advantage may 'e taken of this fact to elimieete one of the knee current-transformers represented at e,

5, and 6 in 3. Any one of these tremeforme e may be omitted without interfering r t with the operation of the instruments or am- LIX meters 14, 15, and 16, and in Fig. 4 I have represented an arrangement differing from Fig. 3 only in that the transformer 5, for example, has been omit-ted. The main 19, into which the secondary of this transformer 5 was formerly connected, still carries current which varies in proportion to the current in the main 2, owing to the fact that it consti "tutes a return-circuit for currents of such values and such phase relations as correspond to the currents in the other mains 1 and 3. g

The invention is not limited to use in connection with three-phase systems, but is applicable to other systems as well and is 09-- erative regardless as to whetherthe system is balanced or unbalanced.

Vihat I claim as new, and desire to secure by Letters Patent of the United States, is

1. The combination of a multiphase alternating-current system, current-transformers for mains ofsaid system, interconnected leads extending from the secondaries of said transformers, and measuring instruments in said leads.

2. The combination of a multiphase alternating-current system, current-transformers therefor, a grounded and interconnected system of leads connected to the secondaries of said transformers, and measuring instruments in said leads.

3. The combination with the mains of a multiphase alternating-current system, of current-transformers for less than the whole number of mains, an interconnected system of The combination with the mainsof a multiphase alternating-current system, of means for measuring the current in'one of the mains, consisting of a measuring instrument and a system of circuits for passing through said instrument a current due to the resultant action of currents. in other mains of said system.

6. The combination with the mains ofa three-phase. alternating-current system, of a system of Y-connected leads, two transformers for conveying three-phase currents inductively from said mains to said leads, and measuring instruments for one or more of said leads.

7. The combination with the mains of a three-phase alternating-current system, of a system of grounded Y-connected leads, two transformers for conveying three-phase currents inductively from said mains to said leads, and measuring instruments for one or more of said leads. V

8. The combination with a multiphase alternating-current system, of current-transformers for all but one of the mains of said s'ystem, interconnected leads extending from the secondaries of said transformers, and measuring instruments in said leads.

9. The combination with the mains of a three-phase alternating-current system, of

current-transformers for two of the mains of said system, an electrical connection between a terminal of. the secondary of one of said transformers and a terminal of the secondary of the other transformer, leads extending from the free terminals of said secondaries and from said connection, said leads being connected together at a common point, and a measuringinstrument inserted in each of said leads.

In Witness whereof I have hereunto set my hand this 25th day of March, 1902.

JONATHA E. W'OODBRIDGE. Witnesses:

BENJAMIN B. HULL, HELEN ORFORD. 

